External chassis device with internal mobile anchorage systems, positioning and automatic pre-fire retention system for long arms

ABSTRACT

External chassis device with internal mobile anchorage systems, positioning and automatic pre-fire retention system for tong arms comprised of external chassis, mobile anchorage by means of internal sliding rings, automatic positioning system by means of a pin and an arm retention system by means of a set of guides and elastic rings integrated in the sliding rings (B) which attach to the body of an arm (D), leaving the barrel free, with free telescopic movement inside an external chassis (A). It also has a positioning pin (G) to block the movement of the arm load and some guide slots (F) for retaining the arm in a fixed position before firing. Elastic rings (H) and screws (I) prevent the rotation of the sliding rings (B) and therefore of the arm (D) inside the chassis (A).

OBJECT OF THE INVENTION

This invention, as expressed in the title of this descriptive report, concerns a device comprised of an external chassis housing a mobile anchorage, a positioning system and an automatic pre-fire retention system for long arms inside, which has been conceived and manufactured in order to obtain numerous and significant advantages over the original design of an EXTERNAL CHASSIS DEVICE WITH INTERNAL MOBILE ANCHORAGE FOR LONG ARMS, Utility Model IS 1203449 U and the subsequent improvement over this previous design, the Utility Model IS 1213804 U IMPROVEMENT OF AN EXTERNAL CHASSIS DEVICE WITH INTERNAL MOBILE ANCHORAGE FOR LONG ARMS THROUGH POSITIONING AND AUTOMATIC PRE-FIRE RETENTION SYSTEM, from the same inventors as this invention. The present invention refers to an external chassis system, inside which there is a mobile anchorage by means of sliding rings, a positioning system and an internal mobile anchorage based on one or several sliding rings, which in turn integrate the automatic pre-fire retention system for long arms, all of them without exposure to the outside, providing greater reliability thereof in the presence of dust, sand or other types of elements than in other systems, avoiding blockages or malfunctions.

Likewise, this external chassis device with internal mobile anchorage systems, positioning and automatic pre-fire retention system for long arms substantially economises its industrialisation by reducing the number of elements, machining tasks and the tolerances thereof required in their manufacture. For this reason, this external chassis device with internal mobile anchorage systems, positioning and automatic pre-retention system for long arms considerably improves the operation of the aforementioned devices thanks to:

1. The incorporation of an arm retention system, housed in the guide rings that slide inside the chassis in a telescopic way with minimum friction.

2. That this retention system fixes the arm in the moments prior to the firing, automatically leaving the arm free in the same moment of the firing.

3. That the system automatically returns the arm to an optimum position when the arm, either by gravity, by impulse of an elastic element or by manual movement, returns to that position.

4. That this system is housed in the guide rings, having no external presence.

5. The incorporation of an element that when loading the arm, by the movement that it entails, leads the arm to the optimum position where the fixed retention system mentioned in points 1, 2, 3 and 4 above, blocks the position of the arm before firing, all independently of the latter.

6. That this retention system is elastic, which brings advantages in its duration, absence of adjustments, absence of lubricants or antioxidants, providing certain flexibility in its tolerances and reducing its cost. All of this facilitates its industrialisation.

The device is described below.

BACKGROUND INFORMATION ON THE INVENTION

The Spanish Utility Model ES 1203449 U, entitled: EXTERNAL CHASSIS DEVICE WITH INTERNAL MOBILE ANCHORAGE FOR LONG ARMS, describes an invention consisting of an external chassis device that allows the displacement, product of the retraction, of the arm inside the external chassis, absorbing this retraction of the arm and avoiding the transmission of movements to the shooter. It also allows the trigger to immediately move away from the shooter's finger, minimising possible “triggerings”.

As a beneficial secondary effect, the mechanisms of the arm's optical target elements do not suffer from the harmful movements associated with the various retractions, as they are located on the external chassis, unrelated to the movements generated by the arm.

But this same characteristic of allowing the movement of the arm, hinders the process of the firing, because when pulling the trigger, if this offers certain resistance, the arm moves and shortens the free travel available to eliminate the retraction. If this happens, the system is not able to absorb the retraction and will then transmit moves to the shooter.

It can also be the case that, in shooting positions with positive or negative angles, gravity itself displaces the arm and the available free travel is again shortened.

An added problem in its daily use arises from the presence of the external guiding system with slots, which can allow any foreign body to enter the interior, in other words, it makes it sensitive to environmental conditions, possibly causing blockages or cleaning difficulties.

To improve the behaviour of the system, an element was included that allows the arm to be fixed until the moment of firing, thus allowing the entire travel of the system to be available to absorb the retraction of the arm. This was described in Utility Model ES 1213804 U, IMPROVEMENT OF AN EXTERNAL CHASSIS DEVICE WITH INTERNAL MOBILE ANCHORAGE FOR LONG ARMS THROUGH POSITIONING AND AUTOMATIC PRE-FIRE RETENTION SYSTEM, where a retention system was added based on a steel ball or similar and a spring, which housed in one of the rings, faced a hole in the cylindrical chassis. Although this system achieved the initial purposes of positioning and blocking prior to firing, it also had the following disadvantages:

-   -   1. The spring had to push the retaining ball continuously with         force, which caused its premature fatigue.     -   2. The limited space available for the dock led to a critical         design of the dock.     -   3. The steel ball rubbed continuously against the wall of the         aluminium cylinder, causing wear on it and the edges of its         housing, reaching a limited life and deterioration of a main         part.     -   4. The presence of a lubricant was necessary to increase the         useful life of the system and its good operation, which in the         presence of dust or sand favoured obstructions.     -   5. The change of the ball from a material like steel to a         polymeric one, reduced the useful life of the system and forced         a periodic replacement of the ball by wear.         The present invention provides all the advantages achieved in         the two systems mentioned above, Utility Models ES 1203449 U and         ES 1213804 U which are the following:     -   1. Eliminate transmission of retraction from the arm to the         shooter's shoulder.     -   2. Reduce the possibility of the “trigger”, in other words,         press the trigger with too much force so that it diverts the arm         in the moment of the firing, since when shooting the arm moves         with its set trigger backwards and the finger of the shooter         stops pressing on it.     -   3. Fix the arm before firing and thereby increase the efficiency         of the retraction eliminator system by allowing it to have all         of the useful travel available.     -   4. Increased sensitivity when triggering the trigger by not         moving the arm when pulling it     -   5. Improvement of the system by firing the arm with positive and         negative angles with respect to the horizontal plane, preventing         the arm, due to its weight, from diminishing the useful path of         the system.     -   6. Greater safety and operating comfort due to the automatic         positioning system which, during the loading process, moves the         arm back to the restraint system without the shooter having to         do so explicitly.     -   7. The system can be applied on already built arms without any         aspect of them having to be modified, since they are clasped by         the sliding rings and these can be fastened to the arm by simple         pressure by means of a screw or taking advantage of threaded         holes already present in the arm, such as the threads of         fixation to the cylinder head.     -   In addition, it also has the following advantages, to a greater         degree than the previous ones:     -   1. With the integrated positioning guidance and retention         system, the system is easier to manufacture, easier to assemble         and therefore more cost-efficient.     -   2. The positioning and guidance system require no maintenance or         adjustment. It does not need lubrication of any kind.     -   3. The guide slots are internal so that the system, besides         being invisible to the user, is more robust to dust or sand and         avoids the possibility of finger entrapment or the intrusion of         foreign bodies into the system.     -   4. The positioning and guidance system is based on an elastic         element, which gives it greater tolerances at the time of         manufacture and use.     -   5. This elastic element is in continuous rest and is not         deformed before and after the firing: it is only at that moment         of the firing, when it suffers compression for tenths of a         second. The service life of this element is therefore almost         unlimited.

Therefore, this new system is more robust and industrialisable.

Therefore, it is an objective of the present invention to make known an external chassis device with internal mobile anchorage systems, positioning and automatic pre-fire retention system for long arms integrated into the interior thereof.

Apart from the documents already mentioned, it is opportune to make reference to another previous invention, the U.S. Pat. No. 4,473,964 A (STRAUB DIETER et al.), which describes an external chassis device with mobile anchorage to absorb the retraction of a long arm comprised of a chassis (3), two rings or sliding bushings (9,10), kinetic energy absorbing element, guide bushing (11), where the chassis houses inside an arm which can slide coaxially thanks to the sliding rings. The longitudinal movement of the arm is absorbed by a spring (col. 4, line 3-28; FIG. 1).

The substantial differences on this invention are as follows:

-   -   a) All the mechanisms described in document U.S. Pat. No.         4,473,964 refer to carbines specifically built for this system         (“Detailed description”, columns 3 and 4) or they must be         severely modified (welds) for their inclusion and to be able to         lodge the sliding guides. In this application, the proposed         system does not imply any modification to a carbine already         existing in the market or in production, as the system is         adjusted externally thereto, by means of screws in the already         existing and generalised anchorages such as the anchorages to         previous cylinder heads, the posterior anchors, stop anchors for         pointing optical elements, etc.     -   b) All the mechanisms described in this document U.S. Pat. No.         4,473,964, FIGS. 1 and 2, always need a guide with an external         support bushing in the rear part of the carbine body. In this         application, the proposed system never needs a guide with an         external eccentric bushing, which gives it greater compactness.     -   c) All mechanisms described in this document U.S. Pat. No.         4,473,964 need a minimum of 2 guides (FIG. 1). In this         application, the proposed system differs in the number of guides         required, with the number of elements B (Slip Rings) ranging         from a single element to multiple elements.     -   d) The mechanism described in document U.S. Pat. No. 4,473,964,         FIG. 1, more similar to the one proposed, sheaths the carbine         barrel and the compression cylinder, positioning without         specifying a way (pressure, perhaps?), two bushings in the         barrel (elements 9 and 10, FIG. 1), while the system proposed in         this application, always leaves the barrel floating and free of         sliding rings or bushings, which is very important in order to         eliminate the pernicious effects of harmonic movements in it.     -   e) The system proposed in U.S. Pat. No. 4,473,964 is based on         high-precision linear bearings on internal cylindrical guides,         while the system proposed here is based on circular elastic         elements on high-tolerance external guides.

DESCRIPTION OF THE INVENTION

Below is a description of the external chassis device with internal mobile anchorage systems, positioning and automatic pre-fire retention system for long arms, starting with a brief description of the different elements it comprises.

A—External chassis containing the arm, element D, the sliding rings, elements B, which clasp around the arm and the absorbing element of kinetic energy C. It is in this element A where the arm's grip components such as pistol grip, cylinder head, handguard, etc. are anchored externally, as well as the aiming elements, whether sight and raise, or telescopic sight, thanks to an 11 mm dovetail rail or to the two drills for screwing on any “Picattiny” or “Weaver” type rail. It also supports the fixing screws, elements I, which block the position of the elastic rings, elements H, which in turn prevent the torsional movements of the arm. B—Minimum friction sliding rings, toroidal in shape, which firmly clasp around the arm and are fastened to it by screwing into the same holes that the arms already have to be anchored to their conventional cylinder head, not requiring modification of the arm, element D. The screws must be below the surface so as not to touch the inner surface of the chassis A. With an adequate dimensioning of the chassis, to adapt element A to different arms, it is only necessary to change or adapt these parts B. The torsion of the arm inside the chassis is avoided with the elastic rings, elements H, which slide internally in the slots, elements F, present in the sliding rings, elements B and which are blocked by the fixing screws, elements I. C—Kinetic energy absorbing element. This element can be a linear or conical metal spring, or an elastomer, or an air compression element or an electromagnet. This C element is optionally unnecessary in cases where the energy released in the retraction is small and can simply be absorbed by the inherent frictions of the system. If necessary, this element C will be in charge of absorbing kinetic energy from the retraction of the arm in either direction. Without changing its properties (such as the elastic constant, for example) we can adapt the system proposed for arms of different power in the mouth and therefore, with more or less strong retractions and more or less distance travelled. Element C is installed inside and at one end of element A. D—Arm itself, not modified after its original manufacture. E—End plug: its mission is to provide anchorage and/or support to the C element and other ergonomic elements such as a cylinder head, for example. Like element C, it is optional, being unnecessary in cases where the energy released in the retraction is small and can be absorbed simply by the inherent frictions of the system. It can also act as a plug for the air compression chamber that is formed when, inside element A, element D linearly travels towards the shoulder of the shooter, being able to compress air or not, by making element B watertight together with element D and acting as a whole as a compression piston that can carry out the mission of element C. With the system at rest, it does not have to withstand any effort. F—Guide slots in the sliding rings, element B. This ensures that element D has no movement other than the coaxial linear to element A. It also provides, by its inner contour, a positioning and retention effect of the element D, which will remain fixed before the firing as the elastic ring H cannot overcome the throttle present inside the slot. At all times this set slot-ring, element F-element H, prevents the rotation of the arm, element D, within the chassis, element A G—Arm positioning pin, which locks the movement of the load and reverses it, placed either on the same external chassis A, or on the handguard of the cylinder head anchored to the external chassis A. This element is necessary in cases of compressed air carbines with lever charge, while in other arms, such as a bolt rifle, it will be unnecessary. H—Elastic rings: Elastomers in the shape of a toroidal washer of a certain thickness which are housed in the guide slots element F, carved in one or all of the rings, elements B. Each of these elements H are fixed in their position together to the chassis element A, by a simple screw, element I screwed to the chassis, element A. I—Fastening screws of the elastic rings, element H. They block the relative position of the rings with respect to the chassis, element A. They are screwed to element A.

As each of the elements H are housed in each of the slots carved in one of the elements B and their position fixed by the screws, elements I with respect to element A, these rings only have a relative longitudinal movement in the same direction as the arm, element D. As can be seen in the figures, the slots have two areas separated by a throttle caused by two small protrusions: An area where the elastic ring is immobilised, element H and another area, where the ring has a useful route free of impediments, always in the direction of the longitudinal axis of the barrel of element A.

When the firing is fired, the retraction force drives the arm, element D, in the opposite direction to that of the projectile or, in the case of compressed air spring carbines, that of the compression element. In this displacement, the elastic rings, elements H, which are solid to the cylinder, element A, thanks to the fixing screws, elements I are subjected to a pulling force and the result is a deformation of the elastic rings H, which causes the sliding rings, elements B, to compress and move, overcoming the throttle present in the guides, elements F. The result is a deformation of the elastic rings H, which causes the sliding rings, elements B, to compress and move, overcoming the throttle present in the guides, elements F. Once the obstacle has been overcome, the sliding ring B presents the part of the slot F with free travel, allowing the elastic ring to move freely, only opposing the rotation movements of the arm, element D.

Elastic rings, elements H, cannot be removed from the immobilisation zone in the face of small forces due to throttle, FIG. 5-(a), but allows such displacement if the force is high enough to slightly deform the elastic ring H, passing through the aforementioned throttle of the slot and returning to its original resting shape in the displacement zone. Thanks also to these opposite slots and the elastic rings, the guidance of the arm inside the cylinder is optimal, not allowing it to rotate inside the cylinder, also giving the elastic nature of the H element, a tolerance margin greater than any other metal retention element.

When the arm, element D, is loaded, thanks to element G or to the shooter's push, it returns to place the rings inside the positioning zone, leaving the arm immobilised until the next firing.

As for the positioning system taking advantage of the moment of loading of the arm, it is necessary to differentiate several possibilities:

1. The arm is loaded with a double backward movement in front of a lever, such as a bolt repetition arm: in the backward movement, for expulsion of the fired cartridge, the arm may reach the end of the run or not, depending on the loading effort and the recovery spring. And in the movement generated to close the bolt and introduce a new cartridge, the arm will again face the retention system, elements H and I. Therefore, in this type of arm, element G is dispensable. Semi-automatic arms with lateral arming lever and repetition arms with lower and trombone (or sliding) lever loading will be considered to be a case similar to the previous one. 2. The arm is loaded with the backward movement of some element, such as a loading lever of a compressed air spring carbine: in this case, when the arm is loaded, by the force exerted on the loading lever, the arm moves backwards. This force is transmitted by means of a connecting rod to the piston rod or piston until it is cocked, compressing the internal spring. By placing element G in the correct position, it blocks the movement of the connecting rod at a certain moment and therefore, by continuing to exert force on the loading lever, this support point causes the arm to move in the opposite direction, forward, automatically positioning the arm in front of the restraint system, elements H and I.

For all these reasons, the novelty of the external chassis device system with internal mobile anchorage systems, positioning and automatic pre-fire retention system for long arms is mainly determined by the aforementioned elements A, B, F, G, H and I and their totally invisible and inaccessible disposition to the shooter when the set is assembled and ready for use.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a vertical view of the complete set of external chassis with internal mobile anchorage systems, positioning and automatic pre-fire retention system for long arms which includes all the elements mentioned, although only the elements A, chassis, D, arm, G, pin and I, fixing screw are visible. The rest of the elements are internal and not visible from the outside.

FIG. 2 shows a vertical view of the arm element D, showing the interior of the system by removing the chassis element A. It shows the assembly of the sliding rings, elements B, the guidance and retention system, elements F, H and I, the automatic positioning pin, element G and the optional elements: the recovery spring, element C and plug E.

FIG. 3 shows a bottom view of the element D arm, the arrangement of the elements B, the elements I fixing screws, and the automatic positioning pin, element G.

FIG. 4 shows element A in lower view showing elements G and I, the latter fixed to the chassis by means of a thread. The holes presented by this element A only have a merely aesthetic purpose.

FIG. 5 presents four detailed views (a, b, c and d) of the guidance and retention system: view (a) shows the profile of the guidance slot element F, machined in element B and with its throttling. In view (b) the elastic ring element H is added, in resting position when the arm is anchored and ready to fire. In view (c) we add the fixing screw, element I that, threaded in the chassis, element A, fixes the elastic ring in a toroidal shape, element H, when crossing it through the internal hole. In view (d) there is a lower view of the sliding ring, element B, in which the fixing screws I and their arrangement are observed, holding the elastic rings, elements H that are not visible.

FIG. 6 shows two isometric views (a and b). View (a) shows all parts except the chassis, element A and optional elements C and E, which make up the external chassis device with internal mobile anchorage systems, positioning and automatic pre-fire retention system for long arms. View (b) includes the cylinder and all systems, although they are not visible for the most part.

The references of the figures correspond to:

-   A. Chassis. -   B. Slip rings. -   C. Kinetic energy absorption element, in this case a metallic     conical spring. -   D. Conventional arm, in this case a piston compressed air carbine. -   E, Plug -   F. Guide slot. -   G. Arm positioning pin -   H. Elastic ring. -   I. Fixing screw.

PREFERRED EMBODIMENT OF THE INVENTION

This preferred form of embodiment, described below, is illustrated in the figures described, in which it can be seen as the external chassis device with internal mobile anchorage systems, positioning and automatic pre-fire retention system for long arms consists of the following essential parts:

A. External chassis that houses all the elements inside. It provides linear motion with minimal friction to elements B. It can also provide support for the installation of gripping elements: cylinder head, handguard, pistol grip. B. Minimum friction sliding rings concentric to the chassis, in this case two, that only provide freedom of movement in the same coaxial axis of the chassis. F—Guide slots present in the sliding rings, element B, which by their shape and with elements H and I, provide retention and guidance of the arm through the rings, elements B. G—Arm positioning pin, which locks the movement of the load and reverses it, placed either on the same external chassis A, or on the handguard of the cylinder head anchored to the external chassis A, This element is necessary in cases of compressed air carbines with lever charge, while in other arms, such as a bolt rifle, it will be unnecessary. H—Elastic rings: Elastomers in the shape of a toroidal washer of a certain thickness which are housed in the guide slots element F, carved in one or all of the rings, elements B. Each of these elements H are fixed in their position together with the chassis element A, by a simple screw, element I bolted to the chassis, element A. Their number can vary from only one to several. I—Fastening screws of the elastic rings, element H. They block the relative position of the rings with respect to the chassis, element A. They are screwed to element A. There will be one for each elastic ring. The following elements also appear in the invention: C. Conical metal spring, which is installed between the arm, element D, and the plug, element E. Absorbs the movement of the arm, element D.

D—Conventional arm.

E—Plug whose mission is to contain the element C and which can be used as a fastening element for the gripping systems: cylinder head and/or pistol grip.

The invention has been described above according to a preferential embodiment thereof, but admits multiple variations without exceeding the object of the claimed invention. These variations can be:

1. Replacement of element C with a cylindrical elastomer. 2. Existence of a single sliding ring of greater length and located at the centre of gravity of the arm 3. Replacement of element I with another type of fixing, such as metal or polymeric pins. 

1. External chassis device with internal mobile anchorage systems, positioning and automatic pre-fire retention system for long arms comprised of external chassis, mobile anchorage by means of internal sliding rings, automatic positioning system by means of a pin and an arm retention system by means of a set of guides and elastic rings integrated in the sliding rings, characterised by the existence of one or more sliding rings (B) which attach to the body of an existing arm (D) without modifying it, leaving the barrel free, with free telescopic movement inside an external chassis (A).
 2. External chassis device with internal mobile anchorage systems, positioning and automatic pre-fire retention system for long arms, according to claim 1, characterised in that the chassis (A) has a positioning pin (G) located in the chassis (A) which blocks the movement of the arm load, changing its direction of movement and positioning the arm (D) in front of the retention system (H and I), which prevents the movement of the arm (D) before firing.
 3. External chassis device with internal mobile anchorage systems, positioning and automatic pre-fire retention system for long arms, according to claim 1, characterised in that it has guide slots (F) integrated in the sliding rings (B), with a special profile with throttle, which allows, in conjunction with the elastic rings (H) and screws (I), the retention of the arm in a fixed position before firing.
 4. External chassis device with internal mobile anchorage systems, positioning and automatic retention prior to firing for long arms, according to claim 1, characterised in that the existence of the set of guides (F) integrated in the sliding rings (B), elastic rings (H) and screws (I) that prevent the rotation movement of the sliding rings (B) and therefore of the arm (D) inside the chassis (A). 